package buymyhome.com.util;

import lombok.val;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @author 杨世博
 *
 * Redis实现全局唯一ID
 */
@Component
public class RedisIdWorker {

    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAMP = 1669334400L;

    /**
     * 序列号的位数
     */
    private static final int COUNT_BITS = 32;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    public long nextId(String keyPrefix){
        //1、生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;
        //2、生成序列号
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        //3、拼接并返回
        return timestamp << COUNT_BITS | count;
    }

//    /**
//     * 获取开始时间戳
//     * @param args
//     */
//    public static void main(String[] args) {
//        LocalDateTime time = LocalDateTime.of(2022,11,25,0,0);
//        long second = time.toEpochSecond(ZoneOffset.UTC);
//        System.out.println("second = " + second);
//    }
}
